A sleeper is a person who is sleeping. "Sleeper" or "sleepers" may also refer to:

A Yo-yo trick, "the sleeper"

Blanket sleeper, a one-piece, footed sleeping garment

In the Captain America comics, a sleeper referred to a giant robot that was installed by the Red Skull in Germany to sleep for twenty years and then destroy the world

An earring, originally one designed to be worn at night (ie while sleeping) to keep the hole in a pierced ear open. In the 1960s, small hoops were often used for this purpose, so this term is sometimes used to describe a small hoop earring. Other people use it to refer to the studs commonly used to pierce ears.

In fantasy sports a player who is drafted late in a draft, but exceeds production from what would be expected from one drafted there.

In business, synonym for sleeping partner

In rail transport, a name for the sleeping car with beds

In construction and shipbuilding, a strong internal beam, especially railroad ties supporting rail tracks

"Sleeper" (Buffy episode), an episode in the seventh and final season of Buffy the Vampire Slayer

Sleeper (film), a 1973 Woody Allen movie

Sleepers (film), a 1996 film

Sleeper hit, a work, such as a movie ("sleeper film"), book, or product, that obtains unexpected recognition or success

Sleeper (fish), a perciform fish of the family Eleotridae

A sleeper is a low inland dike, obsoleted by a new dike closer to the shore

Sleeper (espionage), a secret agent left long inactive

Sleeper (band), a Britpop band in the 1990s

Sleeper (comic book), a comic book published by DC Comics

A type of couch, also known as a fold-out couch or hide-a-bed

Sleeper (car), an automobile that has any manner of modified engine, drivetrain, suspension, brakes or other parts, with the goal of improving its original performance, while still maintaining the outward appearance of a stock, factory equipped vehicle; the British term for this is Q-car

Sleepers (TV series), a British comedy-drama

Sleepers (album), a solo album from Rapper Big Pooh

Sleeper cell, a similar group of agents

A sleeper hold is a type of chokehold in wrestling